The content of the invention
Asked to solve the technology that the larger Zero-order diffractive light beam of intensity in laser projection device diffraction optical element be present
Topic, the present invention propose a kind of adjustable laser projection device of Zero-order diffractive.
In order to solve the above problems, the technical solution adopted by the present invention is as described below:
A kind of adjustable laser projection device of Zero-order diffractive, including:Light source, outwards launch light beam;Substrate, for fixing
State light source;Collimation unit, converges the light beam of the light source transmitting, and outwards projects collimated light beam;Diffraction optical element, receive and
The collimated light beam, and outwards projective patterns light beam are expanded, the patterned beam includes Zero-order diffractive light beam and high-order spreads out
Irradiating light beam;Adjustable zero level suppresses unit, and for receiving and decaying, the zero level derives light beam, and it is adjustable outwards to project intensity
Zero-order diffractive light beam.
Adjustable zero level, which suppresses unit, includes the polarizer and analyzer, and the polarizer and/or the analyzer can rotate;
The angle in the direction that shakes thoroughly of shake thoroughly direction and the analyzer of the polarizer is 0-90 °;The cross-sectional area of the polarizer and the inspection
The cross-sectional area of inclined device is not less than the hot spot cross-sectional area of Zero-order diffractive light beam, and the polarizer and analyzer include linear polarizer.
Adjustable zero level, which suppresses unit, also includes half-wave sheet devices, and the half-wave sheet devices are located at the polarizer and the inspection
Between inclined device;Half-wave sheet devices include rotation mirror holder and half-wave plate, and the rotation mirror holder includes outer ring, rotary body and containing groove
Inner ring, the outer ring are connected with inner ring by rotary body;The groove of the inner ring is used to fix the half-wave plate;Half-wave plate optical axis
Azimuth realize accurate control by rotating the rotatable mirror holder.
A kind of method for manufacturing the adjustable laser projection device of Zero-order diffractive, including substrate and light source are provided, by institute
Light source is stated to be fixed in substrate;Collimation unit and diffraction optical element are provided, by the collimation unit be fixed on the light source with
Between diffraction optical element, for collimating or focusing on the light beam of the light source transmitting, and project and put down to the diffraction optical element
Row light beam;The diffraction optical element, for receiving and expanding the collimated light beam, and to object space projective patterns light
Beam;Adjustable Zero-order diffractive is provided and suppresses unit, the adjustable Zero-order diffractive, which suppresses unit, includes the polarizer, analyzer, or also
Including half-wave sheet devices, the adjustable Zero-order diffractive suppresses the side that unit is arranged on the diffraction optical element outgoing beam,
For the Zero-order diffractive light beam in the patterned beam of accurately adjustably covering or decay.
Beneficial effects of the present invention are:After the collimated unit convergence of laser of light source transmitting, penetrated in a manner of collimated light beam
To diffraction optical element, subsequent diffraction optical element expands collimated light beam for first laser pattern, and the adjustable zero level suppression of directive
Unit processed, suppress the rotation effect and delustring mechanism of unit based on adjustable zero level, effectively can be directed in first laser pattern
Zero-order diffractive light beam carry out accurate attenuation processing, so as to while laser speckle pattern integrality is ensured, further change
The kind laser speckle pattern quality for being projeced into object space;The laser speckle pattern of laser projection device projection has the uniformity
Feature higher, contrast is stronger, and more meet eye-safe standard.
Specific embodiment
The present invention is described in detail by specific embodiment below in conjunction with the accompanying drawings, for a better understanding of this hair
It is bright, but following embodiments are not intended to limit the scope of the invention.In addition, it is necessary to illustrate, the diagram provided in following embodiments
Only illustrate the basic conception of the present invention in a schematic way, the component relevant with the present invention is only shown in accompanying drawing rather than according to reality
Component count, shape during implementation and size are drawn, it is actual when implementing shape, quantity and the ratio of each component can be one kind with
The change of meaning, and its assembly layout form may also be increasingly complex.
The orientation of the instruction such as " on ", " under ", "front", "rear", " interior ", " outer ", "left", "right" it is to be appreciated that term
Or position relationship is based on orientation shown in the drawings or position relationship, is for only for ease of the description embodiment of the present invention and simplification is retouched
State, rather than instruction or imply signified device or element there must be specific orientation, with specific azimuth configuration and operation,
Therefore it is not considered as limiting the invention.
Fig. 1 is optically-active effect schematic diagram of the half-wave plate to linearly polarized light.Half-wave plate is added by certain thickness birefringece crystal
Work forms, and can cause the polarised light of incidence, and its ordinary light produces the optical path difference or 180 ° of phases of half-wavelength with extraordinary ray component
Position delay.In addition, half-wave plate can be used for the polarization direction of rotation linearly polarized light.The linear polarization incident perpendicular to half-wave plate main cross section
Light beam, when the angle of its polarization direction and half-wave plate optical axis is α, the linearly polarized light beam of outgoing, its polarization direction is relative to entering
There occurs the rotation that angle is 2 α for the polarization direction of irradiating light beam.As shown in figure 1, the light beam of light source transmitting, its polarization state and nature
The polarization state of light is similar, has the characteristics of symmetrical, to be uniformly distributed.Natural light 1 is transmitted along the z-axis direction, when natural light 1 is transmitted to inclined
Shake piece 2 when, because the direction that shakes thoroughly of polarizer 2 be y directions, so the linearly polarized light beam 3 only polarized along the y-axis direction can be smooth
By polarizer 2 and continue to transmit along the z-axis direction, and the light beam of other polarization directions covers absorption by polarizer 2.Polarization
When light beam 3 incides half-wave plate 4, because the angle between the polarization direction of linearly polarized light beam 3 and the optical axis 41 of half-wave plate 4 is
So the light beam 5 of outgoing, for the linearly polarized light beam 3 of incidence, its polarization direction occursRotation.
If Fig. 2 is the vertical view figure structure schematic representation of the rotation mirror holder of an embodiment of the present invention, Fig. 3 is of the invention a kind of real
Apply the section figure structure schematic representation of the rotation mirror holder of example.As illustrated, rotation mirror holder 6 is by outer ring 61, rotary body 62 and containing recessed
The inner ring 63 of groove is formed;Wherein, the groove of inner ring 63 is used for the embedded and fixed light action object 64 for needing to rotate.Outer ring 61
It is connected between inner ring 63 by rotary body 62, realizes linkage function.In a kind of embodiment, rotary body 62 by being engaged up and down
Screw thread is formed, and inner ring 63 is fixed on inside and outside rotary body 62 by gluing, welding or other feasible patterns respectively with outer ring 61,
Rotation outer ring 61 causes the upper screw thread generation torsion of rotary body 62 to force lower screw thread to rotate backward, so as to realize inner ring 63 indirectly
Rotation, it is finally reached the accurate purpose for changing the anglec of rotation of light action object 64.It is emphasized that in order to meet light action thing
The adjustable rotary of the high accurancy and precision of body 64, it is desirable to which the screw thread of occlusion up and down of rotary body 62 should well-balanced and equidistantly distributed.
In the alternative embodiments of the present invention, light action object 64 can be half-wave plate, can also be the polarizer or analyzing
Device.
As shown in figure 4, it is the adjustable laser projection device schematic diagram of Zero-order diffractive of an embodiment of the present invention.This implementation
Laser projection device in example includes, substrate 10, light source 11, collimation unit 12, diffraction optical element 13 and the suppression of adjustable zero level
Unit 100 processed.
Light source 11 is fixed on substrate 10 towards the side of collimation unit 12, and launches light beam to collimation unit 12;Collimation is single
Member 12 is used for the light beam for converging the transmitting of light source 11, and projects collimated light beam to diffraction optical element 13;Diffraction optical element 13
The collimated light beam projected for receiving and expanding the collimation unit 12, and suppress the projective patterns of unit 100 to adjustable zero level
Change light beam;Patterned beam includes Zero-order diffractive light beam 14 and high order diffraction light beam 18;Adjustable zero level suppresses unit:Described in reception
Zero-order diffractive light beam in patterned beam, accurate attenuation or the masking patterned beam, and outwards project the patterning
In light beam high order diffraction light beam and decay or masking after Zero-order diffractive light beam.It is emphasized that here expand finger
It is that single beam spread is referred to as beam splitting into multiple light beams.The patterned beam that collimated light beam is formed after expanding can
To be two-dimensional shapes pattern or two-dimensional speckle pattern etc..
Adjustable zero level suppresses unit 100 and is made up of the polarizer 15, half-wave sheet devices 16 and analyzer 17, for flexibly hiding
Cover, the high order diffraction light beam 18 of the intensity for Zero-order diffractive light beam 14 of decaying and transmission in addition to Zero-order diffractive light beam 14.
The polarizer 15 includes linear polarizer 151, the transparent part 152 of non-optical effect, linear polarizer 151 by it is embedded,
The mode of stickup is arranged in transparent part 152, particular location and size by Zero-order diffractive light beam 14 actual facula position and
Size determines.
Half-wave sheet devices 16 are made up of rotation mirror holder 161 and half-wave plate 162;Wherein, at half-wave plate 162, revolving mirror is rotated
Frame 161 can accurately change the azimuth of the optical axis of half-wave plate 162;
The construction of the construction of analyzer 17 and the polarizer 15 is substantially similar, including linear polarizer 171, non-optical effect it is saturating
Bright part 172.
In one embodiment of the present invention, the direction that shakes thoroughly of the polarizer 15 and analyzer 17 is parallel to each other, i.e., line is inclined
The piece 151 that shakes is consistent with the direction that shakes thoroughly of linear polarizer 171, and its cross-sectional area is horizontal not less than the hot spot of Zero-order diffractive light beam 14
Sectional area, it is preferable that linear polarizer 151 and the cross-sectional area of linear polarizer 171 and the hot spot cross section of Zero-order diffractive light beam 14
Product is equal in magnitude.
High order diffraction light beam 18 injects adjustable zero level from the region of transparent part 152 of the polarizer 15 and suppresses unit 100, due to
High order diffraction light beam 18 is natural light, thus high order diffraction light beam 18 can pass through half-wave plate 162 with loss-free, and by analyzing
The region of transparent part 172 of device 17 projects adjustable zero level and suppresses unit 100, is finally projeced into the high order diffraction light of objective plane 19
Beam projected area 191.
Zero-order diffractive light beam 14 injects adjustable zero level by the region of linear polarizer 151 of the polarizer 15 and suppresses unit 100, zero level
Diffracted beam 14 risen through linear polarizer 151 it is to the rear, with the directive half-wave sheet devices 16 of the second Zero-order diffractive light beam 141;Subsequent second
After the optically-active of half-wave plate 162 effect, its polarization direction can occur to deflect to a certain degree Zero-order diffractive light beam 141, and with the 3rd 0
The directive analyzer 17 of order diffraction light beam 142;Due to shake thoroughly direction and the direction one that shakes thoroughly of linear polarizer 151 of linear polarizer 171
Cause, therefore the portion of energy of the 3rd Zero-order diffractive light beam 142 can be linearly polarized piece 171 and absorb, finally with the 4th zero order diffracted light
Beam 143 projects adjustable zero level and suppresses unit 100, and is projeced into the Zero-order diffractive light beam projected area 192 of objective plane 19.
Rotation effect and the polarizer 15, the delustring mechanism of analyzer 17 based on half-wave plate 162, rotate rotation mirror holder
161 change the polarization direction angle α of the optical axis of half-wave plate 162 and the second Zero-order diffractive light beam 141, can accurately deflect the 3rd 0
The polarization direction of order diffraction light beam 142, so as to realize accurate attenuation or regulate and control the luminous intensity of Zero-order diffractive light beam 14.
In order to make it easy to understand, specifically, it is assumed that the luminous intensity of Zero-order diffractive light beam 14 is I0, it is polarized through linear polarizer 151
Afterwards, the light intensity decays of the second Zero-order diffractive light beam 141 are 0.5I0, due to the optical axis and the second zero order diffracted light of half-wave plate 164
The polarization direction angle of beam 141 is α, therefore the polarization direction of the 3rd Zero-order diffractive light beam 142 and linear polarizer 151 and linear polarization
The angle of piece 171 is 2 α, with reference to Malus' law, is projeced into the 4th Zero-order diffractive light beam 143 in the region of objective plane 192, its
Luminous intensity is I=0.5I0*(cos2α)2, i.e. the intensity of the 4th Zero-order diffractive light beam 143 determines by angle α, and angle α takes
It is 0-45 ° to be worth adjustable range.The beneficial effect so set is, according to the luminous intensity of high order diffraction light beam 18, to pass through regulation half
The Axis Azimuth angle of wave plate device 16, accurate attenuation can be carried out to Zero-order diffractive light beam 14, so that it is guaranteed that being projeced into mesh
Mark the patterning laser beam homogeneous distribution in space.
In the alternative embodiments of the present invention, light source 11 can be edge-emitting laser and its array or vertical-cavity surface-emitting
Laser and its array;The wavelength of light source 11 is 850nm, 950nm infrared laser beam or the laser beam of its all band;The polarizer
15 only can also be made up of linear polarizer 151, and by inlaying, pasting or other feasible patterns are fixed on diffraction optical element
13 light extraction side;Analyzer 17 only can also be made up of linear polarizer 171, and by inlaying, pasting or other feasible sides
Formula is fixed on the light extraction side of half-wave sheet devices 16.Now, the cross-sectional area of the polarizer 15 and analyzer 17 should be not less than zero level
The facula area of diffracted beam 14.Further, it should be noted that it is projeced into the 4th zero order diffracted light in the region of objective plane 192
Beam 143, its luminous intensity are I=0.5I0*(cosα)2, the wherein value adjustable range of angle α is 0-90 °.
In the another alternative embodiments of the present invention, the polarizer 15 and the angle in the direction that shakes thoroughly of analyzer 17 are β, i.e. line
Polarizer 171 and the angle of linear polarizer 151 are β.Wherein, β span is 0-90 °.It should be noted that it is projeced into mesh
The 4th Zero-order diffractive light beam 143 in the region of plane 192 is marked, its luminous intensity is I=0.5I0*(cos(β-2α))2Or I=
0.5I0*(cos(2α-β))2, i.e. the luminous intensity of the 4th Zero-order diffractive light beam 143 together decides on by angle α and β.
Fig. 5 is the adjustable laser projection device schematic diagram of Zero-order diffractive of another embodiment of the present invention.In the embodiment
Laser projection device it is roughly the same with the laser projection device in Fig. 4 embodiments, difference is the laser projection device
Another adjustable zero level suppress unit 101 and include:The polarizer 15 and analyzer 20 can be revolved.
The polarizer 15 is similar with the structure of Fig. 4 embodiments, is not repeated to describe herein.
Analyzer 20, which can be revolved, includes linear polarizer 201, the transparent part 202 of non-optical effect and rotation mirror holder 203;Wherein,
Linear polarizer 201 is by inlaying, pasting or other feasible patterns are fixed in transparent part 202, and particular location and size are by zero
The position of the hot spot of order diffraction light beam 14 and size determine;Transparent part 202 is fixed on by way of embedded in rotation mirror holder 203
The groove of side, mirror holder 203 is rotated by rotating, can accurately change the direction that shakes thoroughly of linear polarizer 201.
In one embodiment of the invention, linear polarizer 151, the center of linear polarizer 201 and Zero-order diffractive light beam
14 it is centrally disposed in the same horizontal line, and the cross-sectional area of linear polarizer 151 and linear polarizer 201 spreads out not less than zero level
The hot spot cross-sectional area of irradiating light beam 14, it is preferable that linear polarizer 151, the cross-sectional area of linear polarizer 201 are equal to zero order diffracted light
The hot spot cross-sectional area of beam 14.
High order diffraction light beam 18 by the polarizer 15 and the transparent part 152 of analyzer 20 can be revolved, the region of transparent part 202 is worn
Cross adjustable zero level suppression unit 101 and be directly entered object space, be finally projeced into the high order diffraction light beam projection of objective plane 19
Region 191.
Zero-order diffractive light beam 14 injects adjustable zero level by the region of linear polarizer 151 of the polarizer 15 and suppresses unit 101, zero level
Diffracted beam 14 rises to the rear through linear polarizer 151, and the linear polarizer of analyzer 20 can be revolved with the directive of the second Zero-order diffractive light beam 141
201 regions;Second Zero-order diffractive light beam 141 is projected after the effect of linear polarizer 201 with another 3rd Zero-order diffractive light beam 142
Adjustable zero level suppresses unit 101, and is projeced into the Zero-order diffractive light beam projected area of objective plane 19.Disappearing based on linear polarizer
Ray machine system, the direction that shakes thoroughly that rotation mirror holder 203 changes linear polarizer 201 is rotated, so as to change linear polarizer 201 and linear polarizer
The 151 angular separation α that shakes thoroughly, so as to reach the luminous intensity purpose of accurate attenuation Zero-order diffractive light beam 14.
In order to make it easy to understand, specifically, it is assumed that the luminous intensity of Zero-order diffractive light beam 14 is I0, it is polarized through linear polarizer 151
Afterwards, the light intensity decays of the second Zero-order diffractive light beam 141 are 0.5I0, because linear polarizer 201 and the saturating of linear polarizer 151 are shaken
Angular separation α, therefore the second Zero-order diffractive light beam 141 is after linear polarizer 161 decays, absorbed, with another 3rd Zero-order diffractive
The homed on its target space of light beam 144, with reference to Malus' law, it is projeced into another 3rd zero order diffracted light in the region of objective plane 192
Beam 144, its luminous intensity are I=0.5I0*(cosα)2, i.e., the intensity of another 3rd Zero-order diffractive light beam 144 determines by angle α, and
And the value adjustable range of angle α is 0-90 °.The beneficial effect so set is, can be according to the light of high order diffraction light beam 18
Intensity, the direction that shakes thoroughly that adjustment can revolve analyzer 20 can carry out accurate attenuation to Zero-order diffractive light beam 14, so that it is guaranteed that projection
It is distributed in the patterning laser beam homogeneous of object space.
In the alternative embodiments of the present invention, Zero-order diffractive light beam 14 is polarized with any angle for linear polarizer 151;
The polarizer 15 only can be made up of linear polarizer 151, and by inlaying, pasting or other feasible patterns are fixed on diffraction light
Learn the light extraction side of element 13;Adjustable analyzer only can be made up of linear polarizer 201 and rotation mirror holder 203.
In the another alternative embodiments of the present invention, adjustable zero level, which suppresses unit 101, includes the polarizer and analyzer, its
The middle polarizer and/or analyzer can rotate.It can revolve the polarizer and analyzer that the specific adjustable zero level, which suppresses unit 101,
Combination or the polarizer and the combination of analyzer can be revolved, can also be the combination that can be revolved the polarizer Yu can revolve analyzer.
The adjustable laser projection device of Zero-order diffractive in the present invention can be integrated in depth camera system, spread out based on zero level
The adjustable laser projection device of irradiating light beam intensity, the laser speckle pattern that the projection arrangement of depth camera is projected, its brightness point
The characteristics of cloth is had evenly, i.e. speckle image acquired in the picture capture device of depth camera system, its accuracy is higher,
And then entirety improves depth camera performance, and the depth camera can provide to enter the intensity of laser pattern according to eye-safe
Row adjustment.
Prior art, traditional laser projection device are different from, its diffraction optical element has Zero-order diffractive.This
The laser projection device of design is invented by way of increasing adjustable zero level and suppressing unit, is ensuring laser speckle pattern integrality
While, accurate attenuation processing can be carried out to Zero-order diffractive light beam according to actual conditions, so as to further improve laser speckle
The overall quality of pattern, the laser speckle pattern of laser projection device projection have the spy that the uniformity is higher, contrast is stronger
Sign, and more meet eye-safe standard, damage of the laser to human eye can be avoided to a certain extent.
On the basis of the present invention, reduced using other optical elements of the prior art by the method for decaying or shielding
The intensity of Zero-order diffractive in laser projection device, it should all belong to the claimed method of the present invention.
In the adjustable laser projection device of Zero-order diffractive of the present invention, hardware installation method described above should not
This is considered as limitation of the present invention, and required hardware need to only meet order installation of the present invention, its specific mounting means
Achievable mounting means in the prior art can be used.
Adjustable zero level in the present invention suppresses unit and is readily applicable to be used for the strong of Zero-order diffractive of decaying in other devices
Degree, its specific thought of the application based on the present invention should all belong to invention which is intended to be protected.
In addition, the invention also provides the manufacture method of the adjustable laser projection device of above-mentioned Zero-order diffractive, including provide
Substrate and light source, the light source is fixed in substrate;Collimation unit and diffraction optical element are provided, the collimation unit is consolidated
It is scheduled between the light source and diffraction optical element, for collimating or focusing on the light beam of the light source transmitting;The diffraction optics
Element, for receiving and expanding the light beam, and to object space projective patterns light beam;Adjustable zero level is provided and suppresses unit,
The adjustable zero level, which suppresses unit, includes the polarizer, analyzer, or also includes half-wave sheet devices, and the adjustable zero level suppresses single
Member is arranged on the side of the diffraction optical element outgoing beam, spreads out for the zero level in the patterned beam of covering or decay
Irradiating light beam.
Above content is to combine specific preferred embodiment further description made for the present invention, it is impossible to is assert
The specific implementation of the present invention is confined to these explanations.For those skilled in the art, do not taking off
On the premise of from present inventive concept, some equivalent substitutes or obvious modification can also be made, and performance or purposes are identical, all should
When being considered as belonging to protection scope of the present invention.